The document discusses PHP arrays. It explains how to create, access, and modify array elements using indexes. It also covers common array functions like count(), print_r(), sort(), and more. Examples are provided to demonstrate appending, popping, pushing, and other operations on arrays. The document also discusses multidimensional arrays and using foreach loops to iterate over arrays.

1. Arrays
Strings and regular expressions
Basic PHP Syntax
CS380
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2. Arrays
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 Append: use bracket notation without specifying an
index
 Element type is not specified; can mix types
$name = array(); # create
$name = array(value0, value1, ..., valueN);
$name[index] # get element value
$name[index] = value; # set element value
$name[] = value; # append PHP
CS380
$a = array(); # empty array (length 0)
$a[0] = 23; # stores 23 at index 0 (length 1)
$a2 = array("some", "strings", "in", "an", "array");
$a2[] = "Ooh!"; # add string to end (at index 5)
PHP

3. Array functions
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function name(s) description
count
number of elements in the
array
print_r print array's contents
array_pop, array_push,
array_shift, array_unshift
using array as a stack/queue
in_array, array_search,
array_reverse,
sort, rsort, shuffle
searching and reordering
array_fill, array_merge,
array_intersect,
array_diff, array_slice, range
creating, filling, filtering
array_sum, array_product,
array_unique, processing elements

4. Array function example
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 the array in PHP replaces many other collections in Java
 list, stack, queue, set, map, ...
$tas = array("MD", "BH", "KK", "HM", "JP");
for ($i = 0; $i < count($tas); $i++) {
$tas[$i] = strtolower($tas[$i]);
}
$morgan = array_shift($tas);
array_pop($tas);
array_push($tas, "ms");
array_reverse($tas);
sort($tas);
$best = array_slice($tas, 1, 2);
PHP
CS380

5. foreach loop
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foreach ($array as $variableName) {
...
} PHP
CS380
$fellowship = array(“Frodo", “Sam", “Gandalf",
“Strider", “Gimli", “Legolas", “Boromir");
print “The fellowship of the ring members are: n";
for ($i = 0; $i < count($fellowship); $i++) {
print "{$fellowship[$i]}n";
}
print “The fellowship of the ring members are: n";
foreach ($fellowship as $fellow) {
print "$fellown";
} PHP

6. Multidimensional Arrays
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<?php $AmazonProducts = array( array(“BOOK",
"Books", 50),
array("DVDs",
“Movies", 15),
array(“CDs", “Music",
20)
);
for ($row = 0; $row < 3; $row++) {
for ($column = 0; $column < 3; $column++) { ?>
<p> | <?=
$AmazonProducts[$row][$column] ?>
<?php } ?>
</p>
<?php } ?>
PHP
CS380

7. Multidimensional Arrays (cont.)
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<?php $AmazonProducts = array( array(“Code” =>“BOOK",
“Description” => "Books", “Price” => 50),
array(“Code” => "DVDs",
“Description” => “Movies", “Price” => 15),
array(“Code” => “CDs",
“Description” => “Music", “Price” => 20)
);
for ($row = 0; $row < 3; $row++) { ?>
<p> | <?= $AmazonProducts[$row][“Code”] ?> | <?=
$AmazonProducts[$row][“Description”] ?> | <?=
$AmazonProducts[$row][“Price”] ?>
</p>
<?php } ?>
PHP
CS380

8. String compare functions
8
Name Function
strcmp compareTo
strstr, strchr
find string/char within a
string
strpos
find numerical position of
string
str_replace, substr_replace replace string
 Comparison can be:
 Partial matches
 Others
 Variations with non case sensitive functions
 strcasecmp

9. String compare functions
examples
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$offensive = array( offensive word1, offensive
word2);
$feedback = str_replace($offcolor, “%!@*”,
$feedback);
PHP
CS380
$test = “Hello World! n”;
print strpos($test, “o”);
print strpos($test, “o”, 5); PHP
$toaddress = “feedback@example.com”;
if(strstr($feedback, “shop”)
$toaddress = “shop@example.com”;
else if(strstr($feedback, “delivery”)
$toaddress = “fulfillment@example.com”;
PHP

10. Regular expressions
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[a-z]at #cat, rat, bat…
[aeiou]
[a-zA-Z]
[^a-z] #not a-z
[[:alnum:]]+ #at least one alphanumeric char
(very) *large #large, very very very large…
(very){1, 3} #counting “very” up to 3
^bob #bob at the beginning
com$ #com at the end PHPRegExp
 Regular expression: a pattern in a piece of text
 PHP has:
 POSIX
 Perl regular expressions
CS380

11. Embedded PHP
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CS380

12. Printing HTML tags in PHP =
bad style
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<?php
print "<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML
1.1//EN"n";
print "
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">n";
print "<html xmlns="http://www.w3.org/1999/xhtml">n";
print " <head>n";
print " <title>Geneva's web page</title>n";
...
for ($i = 1; $i <= 10; $i++) {
print "<p> I can count to $i! </p>n";
}
?> HTML
 best PHP style is to minimize print/echo statements in
embedded PHP code
 but without print, how do we insert dynamic content into
the page?

13. PHP expression blocks
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 PHP expression block: a small piece of PHP that
evaluates and embeds an expression's value into HTML
 <?= expression ?> is equivalent to:
<?= expression ?> PHP
CS380
<h2> The answer is <?= 6 * 7 ?> </h2>
PHP
The answer is 42
output
<?php print expression; ?>
PHP

14. Expression block example
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><title>CSE 190 M: Embedded PHP</title></head>
<body>
<?php
for ($i = 99; $i >= 1; $i--) {
?>
<p> <?= $i ?> bottles of beer on the wall, <br />
<?= $i ?> bottles of beer. <br />
Take one down, pass it around, <br />
<?= $i - 1 ?> bottles of beer on the wall. </p>
<?php
}
?>
</body>
</html> PHP

15. Common errors: unclosed
braces, missing = sign
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...
<body>
<p>Watch how high I can count:
<?php
for ($i = 1; $i <= 10; $i++) {
?>
<? $i ?>
</p>
</body>
</html> PHP
 if you forget to close your braces, you'll see an error
about 'unexpected $end'
 if you forget = in <?=, the expression does not produce
any output
CS380

16. Complex expression blocks
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...
<body>
<?php
for ($i = 1; $i <= 3; $i++) {
?>
<h<?= $i ?>>This is a level <?= $i ?>
heading.</h<?= $i ?>>
<?php
}
?>
</body> PHP
CS380
This is a level 1 heading.
This is a level 2 heading.
This is a level 3 heading. output

17. Functions
Advanced PHP Syntax
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CS380

18. Functions
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function name(parameterName, ..., parameterName) {
statements;
} PHP
CS380
function quadratic($a, $b, $c) {
return -$b + sqrt($b * $b - 4 * $a * $c) / (2
* $a);
} PHP
 parameter types and return types are not written
 a function with no return statements implicitly returns
NULL

19. Default Parameter Values
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function print_separated($str, $separator = ", ") {
if (strlen($str) > 0) {
print $str[0];
for ($i = 1; $i < strlen($str); $i++) {
print $separator . $str[$i];
}
}
} PHP
CS380
print_separated("hello"); # h, e, l, l, o
print_separated("hello", "-"); # h-e-l-l-o
PHP
 if no value is passed, the default will be used

20. PHP Arrays Ex. 1
 Arrays allow you to assign multiple values to one
variable. For this PHP exercise, write an array variable
of weather conditions with the following values: rain,
sunshine, clouds, hail, sleet, snow, wind. Using the array
variable for all the weather conditions, echo the following
statement to the browser:
We've seen all kinds of weather this month. At the
beginning of the month, we had snow and wind. Then
came sunshine with a few clouds and some rain. At least
we didn't get any hail or sleet.
 Don't forget to include a title for your page, both in the
header and on the page itself.
CS380
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21. PHP Arrays Ex. 2
 For this exercise, you will use a list of ten of the largest
cities in the world. (Please note, these are not the ten
largest, just a selection of ten from the largest cities.)
Create an array with the following values: Tokyo, Mexico
City, New York City, Mumbai, Seoul, Shanghai, Lagos,
Buenos Aires, Cairo, London.
 Print these values to the browser separated by commas,
using a loop to iterate over the array. Sort the array, then
print the values to the browser in an unordered list,
again using a loop.
 Add the following cities to the array: Los Angeles,
Calcutta, Osaka, Beijing. Sort the array again, and print
it once more to the browser in an unordered list.
CS380
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